1. Field of the Invention
The present invention relates to an iontophoresis device and more precisely relates to an iontophoresis electrode structure.
2. Description of the Related Art
The electrodes which are used for iontophoresis for electrically administering aqueous and ionic drugs through the skin are copresent with the solutions containing the drugs and further are mainly supplied continuously or intermittently with therapeutic current of a one-directional polarity.
Electrodes placed under the above-mentioned conditions unavoidably suffer from reduction of their conductivity due to the electrical decomposition and the changes in chemical properties of the electrodes themselves, covering by an electrical insulator, etc.
On the other hand, in the related conventional technology, such as an iontophoresis electrode structure, various types of structures have been proposed, including ones using a so-called reversible (nonpolarized) electrode.
However, when a reversible electrode is used for iontophoresis, the various types of ions freed from the electrode at the time of conductance cause a remarkable drop in the rate of transport of the ionic drug. Therefore, the object of the present invention is to provide a novel electrode structure making it possible to avoid the reduction of conductivity of the electrodes when the electrodes are used in practice, and to obtain efficient iontophoresis preventing as much as possible the drop in the transport rate.